Knots are usually made to elongated materials manually or with devices. Knots are conventionally used in fishing for attaching lures to fishing lines. Knots may also be used in textile applications for providing knots to yarns or in some other industrial or non-industrial applications. Knots are also produced in medical applications in connection with stitches, surgical operations or the like. In many situations it may be difficult to form knots manually due to weather conditions outside or due to other circumstances. Also some elongated materials have characteristics which make forming knots very difficult, such characteristics comprising rigidity, slipperiness or small diameter of the elongated material. For alleviating the above mentioned difficulties there are different kinds of devices for making knots. One prior art device for forming knots is described in International Patent Application having publication number WO 2007/063175 A1 and published Jun. 7, 2007.
The prior art devices for forming a knot comprise a body, a central cavity inside the body, a material track along which the elongated material is guided in the device, the material track comprising opening extending along the material track and open to the central cavity. The material track is shaped or provided such that it forms a preformed knot to the elongated material. The finished knot may be produced by tightening the preformed knot. The tightening may be carried out by pulling. For forming the knot elongated material is fed into the device such that the front end of the elongated material moves through the geometry of the material track such that the preformed knot is produced. After that the elongated material is pulled from the material track to the central cavity though the opening of the material track. After releasing the elongated material into the central cavity the preformed knot is tightened by pulling and the elongated material with the knot may be removed from the device. The apparatus may be designed such that the elongated material may be attached to an object with the knot. In some embodiments the object, such as a fishing lure, may be connected to the device such that the device automatically attaches the elongated material to the object when the knot is formed.
In the prior art devices the elongated material travels along the material track when it is pushed or drawn. The material track comprises the opening that is open to the central cavity of the device. The central cavity is provided for releasing the elongated material from the material track when the knot is preformed, such that the preformed knot may be tightened to a finished knot. The material track comprises of several turns and curves which the elongated material follows as it travels through the desired geometry of the material track. In the prior art devices the elongated material follows the track during travelling based on the internal tension of the elongated material. If the internal tension or diameter of the elongated material is not in optimal range the elongated material will not remain in the material track. Therefore the elongated material may escape from the material track to the central cavity or simply become stuck in the material track itself. If the internal tension of the elongated material is too high or the diameter too large, the elongated material cannot travel through the turns and curves of the material track. If the internal tension is too low or the diameter too small, the elongated material may fold in the material track preventing the elongated material to travel further in the material track or blocking the material track. According to the above mentioned the problem with the prior art devices is that their operation is limited to only certain types of elongated materials having certain internal tension, diameter and material. This means that separate devices have to be provided for different types of elongated materials.